Regular readers are probably well used to some of my discussions on the possibility of a triad of issues - gut permeability, gut bacteria and immune function - being related to cases of autism. Indeed not so long ago I posted a sort of 'where is research up to' with gut permeability in relation to autism (see here). Already in light of the recent Patterson lab findings on leaky mice guts and immune activation (see here) this megapost is out of date. And now with the Dalton findings it's even more out of date, such is the rapidity of scientific research (and the responsiveness of blogging).

Anyhow, back to the Dalton findings. Well, I've got to really start with a quote from their study: "no statistically significant group difference in small intestine permeability in a population cohort-derived group of children with ASD compared with a control group with SEN". This was based on quite a nice participant number of teens (yes, I'll mention that again) where gut permeability was "assessed by measuring the urine lactulose/mannitol (L/M) recovery ratio by electrospray mass spectrometry-mass spectrometry". That mass spectrometry (MS) mention adds some significant credibility to the detection methods used to assay for those markers of intestinal permeability.

That being said, the devil is in the detail when it comes to the study findings outside the group comparisons between autism and SEN participants. So: "Eleven children (9/103 = 8.7% ASD and 2/30 = 6.7% SEN) had L/M recovery ratio > 0.03". L/M recovery ratios refers to the amount of lactulose and mannitol sugars recovered in urine generally suggested to be below 0.03 to be a 'normal' result (see here). In effect, 8.7% of the children with autism in the Dalton cohort presented with leaky gut.

I have to say that I am a little bit surprised by the Dalton results and how much they contrast with the other work in this area particularly the de Magistris findings** in terms of the percentage of children showing abnormal gut permeability (36% vs. 8%). One might assume that there are potential population differences (UK vs. Italy) or that even age at gut permeability analysis might be an issues. Realising that use of a gluten- and casein-free (GFCF) diet also seems to impact on gut permeability issues (as was perhaps the cases when considering the Robertson paper***) is another potential place to look for reasons for the disparity across the results. If I also had to ask one further thing about the Dalton paper, it would be to have included a typically-developing group alongside their autism and SEN cohorts so we could frame the results with previous data.

In terms of the publication team and very possibly the cohort used for this study, I'm not altogether sure but I think we might have already heard something about these participants insofar as that 'functional bowel problems do seem to be present in autism' work published by Chandler and colleagues earlier this year (see here). I base that on the single result of a participant with autism showing a result representative of "more definitely pathological" gut hyperpermeability (leaky gut) and being subsequently presenting with "undiagnosed asymptomatic celiac disease". Indeed, 1 out of 103 teens with autism presenting with autism is not a dissimilar figure from other work****; bearing in mind the Ludvigsson paper on 'not quite coeliac disease' but something else being potentially related to autism (see here).

So, yet again, more data suggesting that when it comes to gut permeability, autism (at least some cases of autism) is much more deserving of further inquiry. That also 6.7% of the small participant group with SEN also showed potential issues with a leaky gut might also be an important area of future investigation.

Now about zonulin - any takers for a study on that molecule and autism?

ABOUT AUTISM SPECTRUM CONDITIONS

Autism or autism spectrum conditions describe several presentations characterised by core issues with social affect and stereotyped or repetitive actions. Diagnosis is made by observation and analysis of developmental history. These are heterogeneous conditions which can carry various co-morbidities and whilst described as life-long are affected by age and maturation. Autism means different things to different people. To some it means a need for life-long support. To others it is part of the varied tapestry of humanity. To all it means a need to foster a welcoming society with appropriate support and opportunities.